SMD code U4s
Marking codes are not standardised, and the same code is reused by unrelated makers for unrelated parts. Below is every part in our tables printed with it, and any printed with a code that is easy to misread as it, from the manufacturers' own marking tables and published code lists.
The last letter, s, is lower case, which on NXP and Philips parts is a date or factory code, so it was set aside and U4 was searched.
89 parts are printed U4s
Not sure which one you have?
Answer up to 4 quick questions and these 50 parts are ranked, with a meter test that settles it. It works on a dead part too.
EC95810C24B1NSOT-23Voltage supervisor, 3 pins, E-CMOSVoltage supervisorSOT-233 pinsE-CMOS
- What it is
- Voltage supervisor
- Maker
- E-CMOS
- Package
- SOT-23
- Pins
- 3
- Details
- Voltage detector IC: 2.4V±2%, -Reset PPO, Rdt=200ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
EC95810C24C1NSOT-323Voltage supervisor, 3 pins, E-CMOSVoltage supervisorSOT-3233 pinsE-CMOS
- What it is
- Voltage supervisor
- Maker
- E-CMOS
- Package
- SOT-323
- Pins
- 3
- Details
- Voltage detector IC: 2.4V±2%, -Reset PPO, Rdt=200ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
ELM7624LCBSOT-23Voltage supervisor, 3 pins, ELM TechnologyVoltage supervisorSOT-233 pinsELM Technology
- What it is
- Voltage supervisor
- Maker
- ELM Technology
- Package
- SOT-23
- Pins
- 3
- Details
- Voltage detector IC: 2.4V±2%, -Reset PPO, Rdt=150ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
ELM9714CABSOT-89Voltage supervisor, 3 pins, ELM TechnologyVoltage supervisorSOT-893 pinsELM Technology
- What it is
- Voltage supervisor
- Maker
- ELM Technology
- Package
- SOT-89
- Pins
- 3
- Details
- Voltage detector IC: 1.4V±2.5%, +Reset PPO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
ELM9714CBBSOT-23Voltage supervisor, 3 pins, ELM TechnologyVoltage supervisorSOT-233 pinsELM Technology
- What it is
- Voltage supervisor
- Maker
- ELM Technology
- Package
- SOT-23
- Pins
- 3
- Details
- Voltage detector IC: 1.4V±2.5%, +Reset PPO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
ELM9754CABSOT-89Voltage supervisor, 3 pins, ELM TechnologyVoltage supervisorSOT-893 pinsELM Technology
- What it is
- Voltage supervisor
- Maker
- ELM Technology
- Package
- SOT-89
- Pins
- 3
- Details
- Voltage detector IC: 5.4V±2.5%, +Reset PPO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
FES1FSMA2 pins, FagNot recordedSMA2 pinsFag
- What it is
- Not recorded
- Maker
- Fag
- Package
- SMA
- Pins
- 2
- Details
- Si-diode: Ultrafast Recovery, 300V, 1A, <50ns
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
GDZ6V8B-V-GSOD-323Zener diode, 2 pins, VishayZener diodeSOD-3232 pinsVishay
- What it is
- Zener diode
- Maker
- Vishay
- Package
- SOD-323
- Pins
- 2
- Details
- Zener diode: 6.65..6.93V, Izt=5mA, Zzt=40, 200mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
MMSZ5V1TSOD-123Zener diode, 2 pins, MotorolaZener diodeSOD-1232 pinsMotorola
- What it is
- Zener diode
- Maker
- Motorola
- Package
- SOD-123
- Pins
- 2
- Details
- Zener diode: 5.1V±5%, Izt=5mA, Zzt=60, 500mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
6 more parts have no package on record
CZRF3V0BZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Zener diode: 2.93..3.08V, Izt=5mA, Zzt=95, 200mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
CZRQR3V0BZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Zener diode: 2.93..3.08V, Izt=5mA, Zzt=95, 125mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
CZRU3V0BZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Zener diode: 2.93..3.08V, Izt=5mA, Zzt=95, 150mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
EC95810C24C7IVoltage supervisor, E-CMOSVoltage supervisorNot recordedNot recordedE-CMOS
- What it is
- Voltage supervisor
- Maker
- E-CMOS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.4V±2%, -Reset PPO, Td=200ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
EC95810C24C7SVoltage supervisor, E-CMOSVoltage supervisorNot recordedNot recordedE-CMOS
- What it is
- Voltage supervisor
- Maker
- E-CMOS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.4V±2%, -Reset PPO, Td=200ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
NC7NZ17LFairchild SemiconductorNot recordedNot recordedNot recordedFairchild Semiconductor
- What it is
- Not recorded
- Maker
- Fairchild Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- CMOS logic IC: Triple noninverting buffer with Schmitt-trigger inputs
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
Is it dead? One meter test per kind
Parts of the same kind are tested the same way, so each test is here once. Each part above points to its own.
Zener diode
Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.
Working, it reads
About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.
Dead, it reads
- The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
- Open both ways, forward too: failed open.
- Holds well off its rated voltage on the supply test: drifted.
- A soft knee, or a voltage that creeps on the supply test: leaky.
- On the board
- this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
- Compare:
- If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
- Watch for:
- A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Integrated circuit
Voltage with the board powered; ohms from each pin to ground with it off.
Working, it reads
Supply pin at its voltage and the output doing what the datasheet says. Readings between pins depend on the part.
Dead, it reads
- A pin near 0 Ω to ground or to the supply pin where an identical part does not read that: failed short.
- Supply present, output stuck: failed, or its load has.
- On the board:
- A pin shorted to ground on the board can be anything on that net. Lift the pin to be sure.
- Compare:
- The surest reference is the same IC on a working board, measured pin by pin.
- Watch for:
- Its protection diodes can read like junctions between pins, even like a transistor. That proves nothing either way.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Silicon diode
Diode range, part lifted or one leg off the pad. Red probe on the anode.
Working, it reads
About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.
Dead, it reads
- The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
- Open both ways: failed open.
- A reading the wrong way round as well: leaky.
- On the board
- this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
- Compare:
- If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
- Watch for:
- A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
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